Pulsar
PSR J1938+6604
Millisecond pulsar · binary system
A millisecond pulsar spinning 45 times per second: an old neutron star spun up again (“recycled”) by matter transferred from a companion. It shares a 2.467 days orbit with a CO white dwarf. Period, spin-down, distance and orbit come from the ATNF Pulsar Catalogue; the beam geometry is illustrative.
| Type | Pulsar |
|---|---|
| Constellation | Draco |
| Period | 22.259 ms (45 Hz) |
| Period derivative | 2.0×10⁻²⁰ s/s |
| Characteristic age | 18.1 billion years |
| Magnetic field | 6.7×10⁸ G |
| Spin-down luminosity | 7.0×10³¹ erg/s |
| Dispersion measure | 41.2 pc/cm³ |
| Distance | 3,379 pc (11.0 thousand ly) |
| Companion | CO white dwarf (estimated), ~1.03 M☉ |
| Orbital period | 2.467 days |
| Eccentricity | 0.000028 |
| Discovery | 2014 · gbncc |
| Source | ATNF Pulsar Catalogue |
| Right ascension (J2000) | 19h 38m 56.9s |
| Declination (J2000) | +66° 04′ 32″ |
In the sky
Visible from the whole Northern Hemisphere and south to latitude 24° S. North of latitude 24° N it never sets. It stands highest at midnight in July, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 11 thousand years ago. At that time the first farming villages were being founded; there was no writing yet. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 196 million years.